Classic/Antique Car Repair: Transmission, speedometer cable, powerglide transmission

Question
Hello, I have a 1970 Nova with a powerglide transmission. I have replaced the speedometer cable then tested it using a drill and the speedometer works, I have pulled out the plastic gearing from the transmission that the cable hooks to and inspected it, it looks fine, but when driving the speedometer does not work, what could be the problem?

Answer
hi jim
 ok you did everything that I would have done, all I  can think of is the gear inside the tranny might be broken or burned out.As you said the speedometer works with the drill or did any thing fall into the pan when you pulled the gear out of the tranny ? that is all that comes to me.
good luck